Fixed missing argument `validateFeed:`
Fixed missing argument `validateFeed:`

Based on the newest API, `public func createWebFeed(url: String, name: String?, container: Container, validateFeed: Bool, completion: @escaping (Result<WebFeed, Error>) -> Void)`, there should be a `validateFeed:` argument.
brentsimmons/Evergreen,brentsimmons/Evergreen,brentsimmons/Evergreen,brentsimmons/Evergreen